overleaf/services/web/frontend/js/features/editor-left-menu/hooks/use-set-root-doc-id.tsx

import { useCallback } from 'react'
import { useEditorContext } from '../../../shared/context/editor-context'
import { useProjectContext } from '../../../shared/context/project-context'
import useScopeValue from '../../../shared/hooks/use-scope-value'
import { type ProjectSettingsScope, saveProjectSettings } from '../utils/api'

export default function useSetRootDocId() {
  const [rootDocIdScope, setRootDocIdScope] =
    useScopeValue<ProjectSettingsScope['rootDoc_id']>('project.rootDoc_id')
  const { permissionsLevel } = useEditorContext()
  const { _id: projectId } = useProjectContext()

  const setRootDocId = useCallback(
    async (rootDocId: ProjectSettingsScope['rootDoc_id']) => {
      const allowUpdate =
        typeof rootDocIdScope !== 'undefined' &&
        permissionsLevel !== 'readOnly' &&
        rootDocIdScope !== rootDocId

      if (allowUpdate) {
        try {
          await saveProjectSettings({ projectId, rootDoc_id: rootDocId })
          setRootDocIdScope(rootDocId)
        } catch (err) {
          // TODO: retry mechanism (max 10x before failed completely and rollback the old value)
        }
      }
    },
    [permissionsLevel, projectId, rootDocIdScope, setRootDocIdScope]
  )
  return setRootDocId
}